1. Field of the Invention
The present invention relates to antenna device and its assembly method as well as wireless communication terminal and its assembly method, and more particularly, is suitably applied to wireless communication terminals to realize a network by wireless by connecting a variety of electronic equipment one another for example.
2. Description of the Related Art
There has been Local Area Network (LAN), a conventional network configured by connecting various electronic equipment to one another such as personal computers and printers, which are used within an architecture or on the premises.
Various electronic devices are usually connected one another in such a LAN system by means of a dedicated communication cable. However, to dissolve complexity in routing the communication cable connecting such electronic devices, of late there:are cases where a wireless communication terminal is connected to each electronic device, thereby realizing wireless communication among those wireless communication terminals.
As shown in FIG. 1, a wireless communication terminal 1 houses inside its housing case 2 made of a nonconductive material, for example, various circuit elements forming transmitting/receiving circuits and a matching circuit, a circuit board 4 mounted with an antenna element 3 produced of a bar-shaped conductive material as well as a shield 5 case made of a conductive material covering various circuit elements on circuit board 4.
Practically, as shown in FIGS. 2 and 3, formed on a surface 4A of circuit board 4 are an electrode 6A (called xe2x80x9cfeeding point randxe2x80x9d hereinafter) to feed power to an antenna element 3 by means of a conductive pattern, and a wiring pattern 6B to electrically connect feeding point rand 6A to a transmitting/receiving circuit 8 through a matching circuit 7.
Also, a stopper 3A, wider in diameter than antenna element itself 3, is formed at one end of antenna element 3, and a through hole 4B matching the girth of that end of antenna element 3 on circuit board 4 so that it may fit into feeding point rand. 6A.
With the one end inserted into through hole 4B causing stopper 3A to be implanted into surface 4A of circuit board 4, antenna element 3 is connected electrically and mechanically at stopper 3A area to feeding point 6B by means of solder 9.
Thus, wireless communication terminal 1 is designed such that it captures given transmit data supplied from an electric device (not shown in Fig.) into circuit board 4, which is transmitted from transmitting/receiving circuit 8 to other wireless communication terminals via matching circuit 7 and antenna element 3 in order, and such that it also receives data transmitted from other wireless communication terminals at transmitting/receiving circuit 8 through antenna element 3 and matching circuit 7 in order, which is transferred to proper electronic equipment.
For additional information, such a wireless communication terminal 1 is designed such that a shield case 5 inside housing case 2 functions as an electric shield preventing against external noises and electric waves radiated from antenna element 3 going around into various circuit elements in transmitting and receiving.
There has been a tendency that those such as wireless communication terminal 1 are made compact as circuit boards 4 are downsized thanks to the advancement of the mounting technology in recent years.
However, if a wireless communication terminal 1 is used in a bandwidth of about 2.4GHz in transmitting and receiving data for example, an antenna element 3 designed to an electric length of xcex/4 requires a physical length of about 30 mm, and another antenna element 3 designed to an electric length of xcex/2, a physical length of about 60 mm.
Because of the above, as is apparent from FIG. 1, in a wireless communication terminal 1 a projection 10 is formed on housing case 2, with the other end of antenna element 3 housed in projection 10.
In practice, in such a wireless communication terminal 1 housing case 2 is made up of a case half, bottom 2A, and a case half, top 2B formed with projection 10. And, when assembled, the circuit board 4 mounted with the shield case 5 is placed on the bottom 2AX; of the case half, bottom 2A by means of legs (not shown in Fig.), and then the case half, top 2B, is placed over the case half, bottom 2A.
However, in assembling the wireless communication terminal 1 a worker holding the case half, top 2B can not see the antenna element 3 because of the case half, top 2B being a cover, making it hard to;have the other end of the antenna element 3 housed into the projection 10 and to mount the case half, top 2B, on the case half, bottom 2A, resulting in poor assemblage.
In order to solve such a problem, as FIG. 4 shows, it can be thought for a wireless communication terminal 14 to house a circuit board 17 with a shield case 16 attached into the housing case 15 consisting of a case half, bottom 15A, and a case half, top 15B, and to hold an antenna element 19 in a nonconductive antenna holding member 18 implanted in a through hole 15BX formed on case half, top 15B, with a male connector (called xe2x80x9cmale connectorxe2x80x9d hereinafter) 21 electrically connected to antenna element 19 by means of a coaxial cable 20 capable of forming into any shape, electrically and mechanically connected to a female connector (called xe2x80x9cfemale connectorxe2x80x9d hereinafter) 22 mounted on circuit board 17.
As shown in FIG. 5, in assembling wireless communication terminal 14 thus constructed, circuit board 17 mounted with shield case 16 is placed on a bottom 15AX of case half, bottom 15B by means of legs (not shown in Fig.), and antenna holding member 18 housing antenna element 19 is inserted into through hole 15BX of case half, top 15B. Then, with male connector 21 connected electrically and mechanically to female connector 22, case half, top 15B is placed over case half, bottom 15A in a overlapping manner, so that case half, top 15B is easily fixed on case half, bottom 15A because antenna element 19 is housed in antenna holding member 18 in advance.
However, in wireless communication terminal 14 thus constructed, because a coaxial cable 21 connected with antenna element 19 is connected to female connector 22 on circuit board 17 by means of male connector 21 before case half, top 15B is fixed on case half, bottom 15A, coaxial cable 21 comparatively long must be used considering the work to fix case half, top 15B on case half, bottom 15A.
Due to the above, care must be taken in assembling wireless communication terminal 14 in a way that coaxial cable 21 is bent in a given shape so that it would not protrude between case half, bottom 15A and case half, top 15B when mounting case half, top 15B on case half, bottom 15A, which still remains unsolved as a problem.
In view of the foregoing, an object of this invention is to provide an antenna device and its assembling method as well as a wireless communication terminal and its assembling method, with a markedly enhanced assemblage.
The foregoing object and other objects of the invention have been achieved by the provision of an antenna device and a wireless communication terminal. An antenna element is held by an antenna holding member, and a circuit board formed with an. electrode to feed power into the antenna element is held by the board holding member, and the antenna element and the electrode of the circuit board are electrically connected by means of a resilient connecting member by fixing the antenna holding member on the board holding member.
Accordingly, because the antenna element is supported by the antenna holding member in advance it is easy to fix the antenna holding member on the board holding member, enabling the antenna element to be electrically connected to the electrode of the circuit board member of the connecting member by merely mounting the antenna holding member onto the board holding member.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters.